Aluminium
bronze Valves

Aluminium Bronze Valves

Aluminium
bronzes are copper-base alloys with around 5% to 11% aluminium. Iron,
nickel, manganese and silicon are often added to enhance its properties.
Aluminium bronze valves are particularly resistant to corrosion by sea
water where they are most frequently used.

Aluminium
bronzes also have good resistance to sulphuric acid, sulphur dioxide and
other combustion products and also show low rates of oxidation at high
temperatures.

The
most common alloys contain 8% to 11% of aluminium and around 5% each of
iron and nickel. The result is more correctly known as a nickel aluminium
bronze (or NAB for short) and is a duplex (two-phase) alloy with excellent
strength and corrosion resistance. Typical specifications are ASTM B148
UNS C95800 or EN1982 CC333G.

In
comparison with other alloys, NAB in sea water is superior to 316, duplex
and super duplex stainless steels where pitting corrosion and crevice
corrosion are concerned. In corrosion terms, it stands up well against
super duplex stainless steels, and is more cost effective.